<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>03-修改属性.html</title>
</head>
<body>
	<input type="text" value="输入框" id="txt">
	<input type="button" value="点我" onclick="document.getElementById('txt').title='我是点击添加的^_^'">
</body>
</html>